A leading human-related threat to the Florida manatee Trichechus manatus latir os tris is collisions with watercraft, which account for 20−25% of reported mortalities. Quantitative threat assessments do not include information on all known manatee−watercraft interactions. These interactions often result in sublethal wounding, usually leaving multiple fresh external wounds in a variety of patterns. These wounds then resolve into well-healed scars. We characterized and quantified watercraft-related scar patterns (1 pattern = 1 strike event) on 2935 nonperinatal carcasses (>150 cm total length) that were recovered from 2007 through 2016 to compare the number of patterns by life stage, sex, and population region and across years. We used generalized linear mixed models to examine the effects of several factors on the probability of carcasses having scars and on the number of scar patterns per carcass. The models indicated that approximately 96% of adults, approximately 70% of subadults, and approximately 34% of calves had watercraft-related scars. The raw data showed that 1 in 4 adults had been hit 10 or more times; 5 adult carcasses bore evidence of 40 or more strikes. On average, adult females had more scar patterns than did adult males. Manatees on Florida’s west coast had more scar patterns than did those on the east coast, while carcasses from the less populated Everglades had significantly fewer scar patterns than did those from the rest of the state. These results improve our understanding of the extent of sublethal injury of the Florida manatee caused by boat strikes.

中文翻译：

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通过检查海牛尸体上的疤痕来量化亚致死的佛罗里达海牛与船只的相互作用

佛罗里达海牛 Trichechus manatus latir os tris 面临的主要人类威胁是与船只相撞，占报告死亡人数的 20-25%。定量威胁评估不包括所有已知海牛与船只相互作用的信息。这些相互作用通常会导致亚致命伤，通常会留下多种不同模式的新鲜外伤。然后这些伤口会变成愈合良好的疤痕。我们对 2007 年至 2016 年回收的 2935 头非围产期尸体（总长 >150 厘米）上与船只相关的疤痕模式（1 个模式 = 1 次撞击事件）进行了表征和量化，以比较不同生命阶段、性别和人口区域的模式数量和跨年。我们使用广义线性混合模型来检查几个因素对屠体有疤痕的概率和每个屠体的疤痕图案数量的影响。模型表明，大约 96% 的成年人、大约 70% 的亚成年和大约 34% 的小牛有与船只相关的疤痕。原始数据显示，四分之一的成年人被击中 10 次或更多；5 具成年尸体有 40 次或更多次撞击的证据。平均而言，成年女性比成年男性有更多的疤痕图案。佛罗里达州西海岸的海牛比东海岸的海牛有更多的疤痕图案，而来自人口较少的大沼泽地的尸体的疤痕图案明显少于该州其他地区的海牛。